As reported by Santer, Wyke and Warner in their report on their community survey and qualitative study reported in BMC Women's Health, 2007, Jun. 2; 7:8, entitled “What aspects of periods are most bothersome for women reporting heavy menstrual bleeding?”, heavy menstrual bleeding is a common symptom amongst women of reproductive age and that the judgements of women reported in the survey were based on periods as a problem because of the impact of the menstrual symptoms on daily life. The impact on daily life was reported as contingent on social circumstances such as the type of paid work and other responsibilities born by the particular women. The women reportedly said that they made judgements based on what was normal for them, the degree of difficulty in containing blood loss, and the pattern of loss.
As consistently reported, excessive menstrual bleeding, commonly referred to as menorrhagia, is defined as menstrual blood loss of greater than 80 milliletres (ml), per menstrual cycle. See for example “Treatment of Menorrhagia” by Apgar, Kaufman, George-Nwogu, and Kittendorf in American Family Physician, 2007. Jun. 15; 75(12):1813-9. As reported by Engstrom, Rose, Brill, Polehill, and Lukanich in “Midwifery Care of the Women with Menorrhagia”, J-nurse Midwifery, 1999, March-April; 44(2:89-105, approximately one in ten women in the United States experience menorrhagia, and although rarely life-threatening, menorrhagia can have an negative impact on women's lives and its treatment can improve the quality of life for many women with this condition.
It is applicants' understanding that a normal menstrual cycle is 21-35 days in duration with bleeding lasting an average of 5 days and a total blood flow between 25-80 ml. Reportedly it is possible to estimate the amount of bleeding by the number of tampons or sanitary pads a women uses during her period. Further applicants' understand that as a guide, a regular tampon fully soaked will hold about 5 ml of blood.
To applicants knowledge, although the prior art is replete with attempts to provide effective and convenient fluid absorbent undergarments for use in absorbing and containing a range of uterine flow volume and flow rates. In applicants' opinion, there has yet to be achieved an optimized flow retention solution which provides for containment of relatively heavy bleeding while minimising the impact of wearing such an absorbent garment on the daily life of the women users so as to reduce the women's daily problems associated with the impact of menstrual symptoms. In particular, it is often desired by women to wear garments where for example in an office work environment or in social evening wear, it is undesirable to exhibit so called panty-lines. Panty-lines are the outline depressions caused by the elasticized leg bands of panty-style underwear. Panty-lines are apparent through clingy fabric or closely conformal garments extending over the buttocks of the user, whether the garments be closely fitting dresses or the like made of light or clingy fabric, or a range of garments between shorts and pants which often provide only a smooth surface over the buttocks of the user. For such occasions, women will typically wear an undergarment commonly referred to as a thong which, in order to remove visible panty-lines, has a narrowed rear portion which extends along the depression between the buttock's cheeks. Typically a thong is asymmetric front to back where the front or crotch portion extending between the saddle (which extends under the perineum) and the waistband is larger or wider than the rear portion in terms of its surface area. The rear portion of the thong is deliberately narrowed so as to conceal the lower edges of the back or rear portion of the thong which extends from the saddle up between the depression or in fact literally between the cheeks of the buttocks. A thong may, above the narrowed portion, flare in the upward extremities of the back or rear portion so as to flare where the rear portion joins the waistband. Indeed in some thongs, as defined herein there is minimal flaring of the back or rear portion as it extends upwardly from the buttock area to the waistband.
It is applicants' experience that for women experiencing moderate to heavy flow, which as defined herein is estimated to fall within the reported definition of the norm, that is, a total blood flow between 25 ml and the statistical abnormality of 80 ml constituting menorrhagia, the available sanitary pad products are ill-suited for use when the woman user desires to wear a thong. This forces a woman to either use a tampon which she may not find effective or otherwise unsuitable for what ever reason, or to forgo the use of a thong for several or more days per menstrual cycle. In applicants' experience, the reason for the unsuitability of presently available products or those applicants are aware of the prior art, is that the designers of such products appear to assume that in order to provide maximum absorbency, that the bulk of the uterine flow is to be absorbed and mostly retained directly under the vagina and vulva. It is an object of the present invention to provide an absorbent thong-style pad for use with a thong, and in one embodiment, to provide a disposable thong having a built in thong-style pad which provides sufficient absorbency for use within the reported range of normal uterine flow rates and yet which will provide for a woman user to wear a thong while supporting such a pad. The problem thus addressed by the present invention is that of dealing with moderate to heavy menstrual flow flowing into a considerably narrowed saddle portion of the pad, hence “thong-style”, which in use is under the vagina, vulva and perineum.
The narrowed portion of the saddle corresponds both to the narrowed waist of the thong underwear and to the narrowed available space between the thighs of the user. The narrowed portion of the thong-style pad according to the present invention is intended to replace the typically quite wide so-called maxi-size sanitary pads which are so wide through the saddle that they have to be bent or buckled to fit, or naturally do so during use, so that the portion intended to capture and retain flow is buckled or folded along a crease line following the crease of the perineum. It is one object of the present invention to provide a narrowed capture zone in the pad saddle which is adapted to guide flow from directly under the vagina and vulva and away to reservoir portions in the front and rear of the pad in order to avoid the flow over-filling the capture zone, and thence over-flowing causing leakage from the pad.
In the patent prior art, applicant is aware of U.S. Pat. No. 2,748,772 which issued to Titone et al for a Disposable Combined Panty and Sanitary Napkin. Titone et al disclose a panty formed of inexpensive cloth material having a pocket like crotch portion to wholly enclose a sanitary napkin. The crotch portion incorporates a piece of flexible material such as thin plastic to ensure against passage of menstrual discharge to the body portion of the panty in which the napkin is supported. Stitching is applied throughout the periphery of the inner wall, extending about the napkin and passing through the marginal area of the inner wall and through the body portion of the panty.
U.S. Pat. No. 3,599,640, which issued Aug. 17, 1971, to Larson for A Disposable Undergarment with Absorption Pad, discloses a disposable waist supported garment including an integral absorbent crotch pad. The components parts of the garment are heat formed and heat sealed. The edges are crimped to form a ribbed effect which is stretchable to sit against the body of the user. The pad is permanently secured to the crotch of the undergarment by a suitable adhesive or by heat sealing, etcetera.
U.S. Pat. No. 4,560,381, which issued Dec. 24, 1985, to Southwell for A Disposable Panty for Menstrual Wear discloses a woman's panty for removably carrying a feminine napkin. It is taught to include a lightweight disposable biodegradable mesh-like outer panty shell to which is affixed or is contiguous with a relatively thick inner layer of absorbent material disposed above the inner surface of the lower body portion of the panty. An elongated, nearly rectangular depression or indentation having oval end portions is included or formed in the relatively thick layer for carrying, lining or positioning a feminine napkin.
U.S. Pat. No. 4,690,681, which issued Sep. 1, 1987, to Haunsehild et al for A Disposable Leak Proof Catamenial Device discloses a panty-like garment containing an integral menstrual pad. The absorbent pad is taught to extend from the crotch region up in both the back and the front to a point which is higher than normal menstrual pads. It is disclosed that the pad extends at least to the area where the crack between the gluteus maximus ends. It is further taught that an impervious member outside of the absorbent pad is greater in area than the absorbent pad. It is also disclosed that the garment may be constructed by placing an absorbent pad on an impervious backing placing a permeable member over the pad and sealing the impervious member and the permeable member together by ultrasonic's where they contact each other outside of the absorbent member, the composite absorbent structure then being bonded to the crotch section of the panty.
U.S. Pat. No. 4,940,463 which issued Jul. 10, 1990, to Leathers et al for A Disposable Combined Panty with Sanitary Napkin discloses a disposable panty having a tubular body portion with an hour-glass configuration to provide an intermediate crotch portion. A sanitary napkin is disposed within the crotch portion. The sanitary napkin includes a frame member provided with absorbent balls disposed in the opening of the frame member to increase the absorption of the menstrual discharge. A flexible liquid impervious material is disposed between the outer layer of the body portion and the sanitary napkin.
U.S. Pat. No. 5,441,493, which issued Aug. 15, 1995, to Gonzalez-Anguiano Marsel et al for Disposal Panties discloses using a sanitary napkin member which is positioned over a longitudinal under-crotch portion of the under pant body of a disposable pair of underpants. The sanitary napkin is only secured to the under pant body along the inner surface thereof and only along the rear and longitudinal edges of the sanitary napkin. An increased density material is provided within the under-pant body at the rear end portion thereof coextensive with the longitudinal under-crotch portion to resist tearing of the rear end portion during flexing of the underpants. The sanitary napkin includes a mini sanitary towel which is attached to the perineum area of the panties by stitching. The central area of the towel is thicker than the front and rear areas.
U.S. Pat. No. 5,745,922, which issued May 5, 1998, to Rajala et al for a Disposable Garment and Related Manufacturing Equipment and Methods, discloses a disposable garment for holding a primary absorbent sanitary pad. Backup protection is provided to control egress for fluids around or through the primary sanitary pad. A secondary absorbent is positioned in the crotch area and extending into the body of the disposable garment to trap leakage from the garment and to trap leakage from the primary absorbent. Elastics extend along the leg openings to form puckers about the leg openings at the edges thereof. The width of the crotch portion is wide enough to accommodate laying the primary absorbent without having the primary absorbent obstruct the crotch elastics. This is taught to allow the crotch elastics to contract and draw up the sides of the crotch about the primary absorbent to contain leakage from the primary absorbent. The width of the crotch portion between the elastics is taught to be not so wide as to seem bulky or uncomfortable, a suitable width being given of at least about 2.75 inches between the crotch elastics, the crotch elastics being taught to be approximately ⅓ to ½ of an inch wide. It is disclosed that the overall width of the crotch portion should be at least about 4 inches. It is taught that preferably the width of the secondary absorbent is equivalent to the overall width of the crotch portion and that the secondary absorbent should have a total capacity of ½ the capacity of the primary absorbent. It is taught that the position and shape of the leg openings are important to avoid tightness in the crotch and groin area and to obtain adequate buttocks coverage.
U.S. Pat. No. 6,231,558, issued May 15, 2001, to Mosley for A Sanitary Undergarment discloses an undergarment which is disposable and which contains a middle region having resiliently elastic material adapted for constricting the middle region around a wearer. A lower region includes a substantially water impermeable material for preventing the passage of menstrual fluids. The lower region is beneath the middle region and includes a crotch region having a primary absorbent pad, and a secondary absorbent pad on the primary absorbent pad. Resiliently elastic leg bands are provided around the outer perimeter of the leg openings. Absorbing strips extend along a semi-circular lower portion of a circumference of the adjacent associated leg opening to absorb fluid in the lower region that may accumulate near the leg openings.
U.S. Pat. No. 6,193,703, issued Feb. 27, 2001, to Jackson for an Adjustable Scroll Absorbent Article and Method discloses providing side leakage protection and positioning guidance for an undergarment. A liquid-impermeable baffle provides the side leakage protection.
U.S. Pat. No. 5,683,373, issued Nov. 4, 1997, to Darby for a Sanitary Napkin Shaped for Use with a Thong Garment discloses a napkin which is generally v-shaped so that the vertex of the “V” can be positioned below the vagina of the wearer. It is designed so that the narrowest tip portion of the napkin terminates just beyond the lower most portion of the vagina, so as to terminate shorter than usual designs. There is no back portion. The top end of the napkin is bulb shaped.
U.S. Pat. No. 7,759,540, issued Jul. 20, 2010, and published Jan. 29, 2004, under publication no. US2004/0019338, to Litvay et al for Absorbent Articles Containing Absorbent Cores having Zoned Absorbency and Methods of Making Same, discloses the use of specific placement of adhesives or specific lack of adhesives to provide zoned absorbency in the absorbent core of an absorbent article. Litvay teaches the use of adhesive (295) in a number of different embodiments to cause more tow fibers (288) and super-absorbent polymer (SAP 286) to adhere in regions where the adhesive is applied thereby providing greater zones of absorbency in specific areas on the absorbent laminate core. It is taught as preferred that the adhesive is applied in a spiral manner, and more particularly to provide a curtain coat of the adhesive intermittently to the upper and lower layers, and not to apply the adhesive in a spiral pattern in the areas where zoning of the SAP is desired. It is disclosed that by not employing the adhesive to either the top or bottom layers of the absorbent laminate core, increased concentration of SAP can be provided in the areas of the cores where it is need most, the example being given of the lowest portion of the core as being beneficial since most liquids tend to migrate to the lowest gravitational point of the core. The example is also given of enhanced absorbency near the lateral edges of the core (FIG. 3).